Given that the image of the function f (x) = ax 3 + bx2 passes through the point m (1,4), the tangent of the curve at the point m is just perpendicular to the straight line x + 9y = 0. Find the values of a and B Hurry! Where's the exam(

Given that the image of the function f (x) = ax 3 + bx2 passes through the point m (1,4), the tangent of the curve at the point m is just perpendicular to the straight line x + 9y = 0. Find the values of a and B Hurry! Where's the exam(


f(x)=ax^3+bx^2
f'(x)=3ax^2+2bx
Because of passing point m (1,4)
So f (1) = 4
So a + B = 4
The tangent of the curve at point m is just perpendicular to the line x + 9y = 0
Then f '(1) = 9
So 3A + 2B = 9
The solution is a = 1, B = 3